The present invention relates generally to a ring laser gyro and, more particularly, to a ring laser gyro comprising a triangular-shaped block design and a symmetrical electrode arrangement on the three sides of the triangular-shaped block for producing two counter propagating laser beams and further comprising gas reaming bores wherein the electrodes are connected by the gas reaming bores inclined to the base leg of the block.
Such a ring laser gyro is known, e.g., from German Patent DE-OS No. 28 39 066. There, symmetrical to the center line of a triangular-shaped block design, two anodes are arranged on the side legs of the laser block and one cathode is arranged on the base leg of the laser block. In this known design both partial gas discharge passages between the anodes and the cathode extend via corner points of the block. Mirrors having a sensitive high reflecting coating are arranged in the corner points. Those mirrors are degraded by the bombardment with ions or electrons respectively from the gas plasma which results in a reduced useful life of the ring laser gyro. In order to prevent the deterioration of the mirrors it is already known to provide a barrier in front of each mirror so that the mirror is isolated from the gas discharge path (see, for example, French Patent No. 20 30 688).